BRPI0721064A2 - PROCESS FOR CONTROLLED HYDROGENATION OF KETOSIS OR SUGAR MIXTURE CONTAINING KETOSIS - Google Patents

Description

"PROCESS FOR THE CONTROLLED HYDROGENATION OF KETOSIS OR SUGAR MIXTURE CONTAINING KETOSIS"

The present invention relates to a process for hydrogenating a sugar or a sugar mixture to produce a product mixture consisting of at least two stereoisomeric sugar alcohols. Fundamentals of the invention

Keto sugars (ketoses) or ketoose-containing sugar mixtures (educts) are typically hydrogenated with hydrogen in an aqueous ketoose cis / ketoose containing mixtures at a high temperature and pressure in the presence of a catalyst. This ketosis hydrogenation usually results in a ratio of the corresponding sugar alcohol epimers of approximately 1: 1.

With this type of educt it is possible to prepare mixtures of sugar alcohols where the ratio of epimers is different from 1: 1. There is a growing interest in improving sugar-free products composed of 1,1-GPM and 1,6-GPS enriched mixtures. Applications of these enriched mixtures are disclosed, for example, in US 6,562,392.

It is therefore desirable to develop a process for certain applications which produces reaction products with a predetermined ratio and eventually a ratio that is different from 1: 1.

The prior art makes several attempts to produce mixtures of stereoisomer mixtures (epimers) where the relationship between said epimers is controlled (predefined).

Several documents provide processes for the production of sugar alcohols from sugars (e.g., WO 2006/063600 A1, DE 2520 173, US 3,912,804, US 6,020,472, Chen et al., Applied Catalysis A. General , 280 (2005), pp. 17-46, Albert et al., In: Moser: Catalysis of Organic Reactions (1978), pp. 421-439) at different catalyst temperatures and concentrations. However, typically the disclosed processes achieve an epimer ratio of approximately 1: 1. In any event, control of the relationship between said epimers is not dealt with in these documents.

DE 2217 628 presents the production of 1,6-GPS only

by hydrogenation of isomaltulose, when alkaline salts are added in the hydrogenation process, so that the pH of the sugar solution is above 9 after hydrogenation.

US 3,329,629 discloses the production of mannitol and sorbitol from an aqueous mixture of glucose and fructose under conditions where the pH value of the aqueous mixture is adjusted such that hydrogenation is performed under neutral, and then alkaline, conditions. and finally acidic.

US 5,679,781 discloses the hydrogenation of isomaltulose using ruthenium and / or nickel as a catalyst at a pressure below 50 atmospheres (5.1 mPa). According to this presentation, 1.1-GPM and 1.6-GPS are obtained in weight ratios between 38:68 to 62:38; However, here, too, the control of the relationship obtained is not addressed.

EP 1 048 637 A1 describes a two step process of converting glucosone into a mixture of product containing mannitol and sorbitol in a ratio of at least 3.5.

US 5,936,081 discloses selective isomaltulose hydrogenation for the production of a mixture of 1-OaD-glucopyranosyl-D-mannitol (1,1-GPM) and 6-OaD-glucopyranosyl-D-sorbitol (1,6- GPS), occasionally referred to as mannitol and sorbitol epimers, respectively. As stated herein, the composition of the products (i.e., the ratio of epimers) may be controlled by hydrogenation of isomaltulose over a predetermined stoichiometric relationship between hydrogen and the educt. With an increase in the hydrogen / isomaltulose ratio, the ratio of mannitol / sorbitol polymers should be reduced. Therefore, if the proportion of the sorbitol epimer should be high (thereby reducing the ratio of mannitol / sorbitol epimer), especially high hydrogen pressures would be required and / or the isomaltulose educt flow would have to be reduced. Both options are not economical.

Therefore, there is a need in the prior art for the

adjusting the stereo-selectivity of the hydrogenation reaction such that one of the stereoisomers is formed in larger proportions than the other stereoisomer. Accordingly, it is desirable to produce a process which produces reaction products having a predetermined ratio of at least one of the two stereoisomeric sugar alcohols (epimers) resulting from the hydrogenation of a ketosis or a ketosis-containing sugar mixture. The invention

The present invention suggests a process for the hydrogenation of a ketosis or a ketosis-containing sugar mixture to produce a product mixture composed of at least two stereoisomeric sugar alcohols, ie the isomer is and the trans alcohol isomer which is composed of heating a reaction mixture consisting of ketosis or a sugar mixture containing ketosis in the presence of hydrogen with a specific predetermined concentration of a solid nickel-based catalyst at a predetermined specific initial temperature and a heating rate from initial temperature (Ti) to final temperature (T2). In this hydrogenation reaction, the relationship between the isomer product and the trans isomer product can be controlled by

(i) by varying the concentration of the solid catalyst based on nickel, preferably Raney nickel;

(ii) by varying the initial temperature of the heating step,

and / or

iii) By varying the heating rate of the

heating. More precisely, the ratio of the isomer to the trans isomer is reduced

(i) by increasing the concentration of the nickel-based solid catalyst, preferably Raney nickel; (ii) by reducing the initial temperature of the nickel

heating, and / or

iii) by reducing the heating rate of the

heating.

Alternatively, the ratio of the isomer to the trans isomer is increased.

(i) by reducing the concentration of the solid nickel-based catalyst, preferably Raney nickel;

(ii) increasing the initial temperature of the heating step, and / or

iii) increasing the heating rate of the

heating.

The isomer refers to the useful configuration of the hydroxyl groups on the C 2 -C 3 carbon atoms of sugar alcohols, while the trans isomer refers to the trans configuration of the hydroxyl groups on the C 2 -C 3 carbon atoms of sugar alcohols.

This process can be advantageously used in the hydrogenation of fructose, sorbose, erythrulose, trehalulose, maltulose, isomaltulose, eucrose, fructooligosaccharides, and mixtures thereof. Preferably, isomaltulose, trehalulose, fructose and mixtures thereof are hydrogenated. In an especially preferred embodiment, the process of the present invention utilizes a reaction mixture composed of isomaltulose (6-O-α-D-glucopyranosyl-D-fructose). Therefore, the stereoisomeric sugar alcohols obtained by hydrogenation of isomaltulose containing a mixture of reagents contain 1-OaD-glucopyranosyl-D-mannitol (1,1-GPM, the isomer) and 6-OaD-glucopyranosyl-D-sorbitol. (1,6-GPS, the trans isomer) in a controlled (predefined) relationship.

Isomaltulose is alpha-D-glucopyranoside-1,6-fructose and can be prepared from sucrose by enzymatic conversion using live or immobilized cell systems by known methods.

Trehalulose refers to D-glucopyranoside-1,1-fructose. Lactulose is 4-beta-galactopyranosyl-D-fructose. Leukrose refers to 5-alpha-glucopyranosyl fructose. Erythrulose is a tetrose carbohydrate of the chemical formula C4H804, also known as 1,4,4-trihydroxybutan-2-one.

The process of the invention may also be advantageously used for the hydrogenation of keto sugar mixtures such as the isomaltulose and trehalulose mixture described in EP 625578.

In another preferred embodiment, the hydrogenation reaction mixture is fructose, resulting in the stereoisomeric sugar alcohols mannitol (isomer) and sorbitol (trans isomer) in a controlled relationship (predefined mannitol / sorbitol).

Typically, the reaction mixture is an aqueous solution composed of ketosis or a sugar mixture containing ketosis in a concentration of 10% to 70% by weight (as dry material). Preferably, the ketosis or ketosis-containing sugar mixture is present in the aqueous solution at a concentration of from 15% to 60% by weight, and more preferably from 30 to 50% by weight.

Hydrogenation may be performed at a hydrogen pressure of from about 10 to 450 bar (1000 to 4000 kPa), preferably from 90 bar (2000 to 9000 kPa). The process may be performed in a continuous mode, semi-continuous or batch mode.

In the process according to the present invention, the ketoses or sugar mixtures containing ketosis are hydrogenated in the presence of hydrogen and a solid nickel based catalyst, preferably a Raney nickel catalyst. These Raney catalysts may be used in various forms as described in the prior art (e.g., cf. Chen et al., Applied Catalysis A. General, 280 (2005), pp. 17 - 46, and references cited therein). ). With the process generally being performed in the liquid phase, the catalyst mixture with the remainder of the reaction mixture will be a heterogeneous mixture. The solid nickel based catalyst used in the context of the present invention is favorably used at a concentration of 0.5% to 10% by weight, preferably between 1% and 8% by weight, more preferably between 2% and 10%. 7%, all based on the dry sugar content of the ketosis or the ketosis-containing sugar mixture.

The inventor surprisingly found that by maintaining the same reaction parameters, but by varying the catalyst concentration between different experiments, the ratio of epimers can be significantly altered. Thus, in one embodiment of the invention, the relationship between the isomer and the trans isomer is controlled by adjusting the concentration of the solid nickel-based catalyst. The predefined ratio of the epimers can be obtained by changing the catalyst concentration. The higher the catalyst concentration, the higher the trans isomer and the lower the sugar alcohol isomer resulting in the reaction mixture. The concentration of the nickel-based solid catalyst can be adjusted (at a given hydrogen pressure), for example,

- by changing the amount of catalyst for a given volume of sugar solution and sugar solution concentration in a batch process with agitation;

- by changing the concentration of the sugar solution to a

determined volume of sugar solution and a certain amount of catalyst in a batch batch process;

changing the volume of the sugar solution to a certain concentration of sugar solution and a certain amount of catalyst in a batch process with agitation;

- changing the volume of the hourly washed sugar solution over a given volume of catalyst and a given concentration of sugar solution;

- by changing the concentration of the washed sugar solution over a given volume of catalyst and a given volume of sugar solution per hour.

The last two options, for example, can be applied to a fixed bed continuous reactor.

The present inventor has further found that the resulting epimer ratio can also be controlled by changing the initial temperature of the heating step. Accordingly, another embodiment of the present invention is characterized in that the initial temperature is adjusted to control the ratio of at least two stereoisomeric sugar alcohols obtained in the hydrogenation reaction. By reducing the initial temperature of the heating step, the ratio of the isomer to the trans isomer is reduced.

Preferably, the reaction is carried out at a temperature between 20 ° C and about 150 ° C. The higher the initial hydrogenation reaction temperature, the more isomer and less trans isomer of the resulting sugar alcohol will be produced. For example, to obtain a specific ratio between the epimers, the initial temperature may be below 40 ° C, such as about 30 ° C or about 20 ° C. Alternatively, the initial temperature may be in the range of 45 ° C. at 65 ° C, such as around 50 ° C, or it may be above 70 ° C.

The desired ratio of epimers, and thus the initial temperature of the hydrogenation reaction required to achieve this ratio, can be produced in various ways, such as

feeding a sugar solution to a catalyst suspension under a hydrogen pressure in a batch reactor at a specific initial temperature;

adding the catalyst in a sugar solution to a batch reactor and then pressurizing the reactor with hydrogen at a given initial temperature; or

continuously feeding a sugar solution into a reactor containing a fixed bed solid catalyst at a given initial temperature.

Furthermore, surprisingly, the inventor found that by maintaining the same reaction parameters but varying the rate of heating in different experiments, the relationship between the epimers can also be changed. Accordingly, an embodiment of the present invention is characterized by adjusting the heating rate to obtain the desired ratio of the isomer to the trans isomer of the obtained sugar alcohols. Thus, by reducing the heating rate of the heating step, the ratio of the isomer to the trans isomer is reduced.

The reaction is further composed of heating said reaction mixture which is a step of heating from an initial temperature (Ti) to an ultimate temperature (T2) having a temperature difference T2-T1 of at least 20 ° C or at least 30 °. C, which may be extended to 130 ° C. For example, this heating step could also be implemented through a gradual growth rate, such as a regular or constant heating rate. A preferred heating rate is less than 6 ° C / min. In a more preferred embodiment of the invention, the heating rate is within a range of 0.5 to 5.0 ° C / min.

In the practice of the present invention, the starting temperature may be room temperature (such as 20 ° C; room temperature) and the final temperature is the desired temperature to complete conversion / hydrogenation of ketosis or sugar mixture containing ketosis to sugar alcohols. stereoisomers (e.g. 130 ° C). Preferably, the temperature difference Ti-T1 is in the range of 40 - 70 ° C or greater. For example, the reaction could be started at 50 - 60 0C and stopped at the final temperature of 100-120 0C. In a specific embodiment, it is preferable to conduct the process with an initial temperature of 20 ° C to 35 ° C to achieve with the heating rate a final temperature of 120 ° C to 140 ° C.

In a preferred embodiment of the present invention the process relates to hydrogenation of a reaction mixture composed of isomaltulose so that at least two isomeric sugar alcohols produced constitute 1,1-GPM and 1,6-GPS. With the processes according to the present invention a wide range of GPM / GPS ratios can be obtained from the same starting material by choosing the appropriate catalyst concentration while taking into account that the other parameters of reaction, such as the heating rate and the initial temperature are also chosen appropriately. Additionally, or alternatively, a wide range of GPM / GPS ratios may also be obtained from the same starting material by choosing the appropriate heating rate and / or starting the reaction at an appropriate starting temperature, provided that the concentration of the catalyst is also appropriately chosen. In this way, for example, GPM / GPS ratios of between 0.6 and 1.2, or even between 0.55 and 1.25 can be obtained.

In a specific embodiment, 50% hydrogenation of dry isomaltulose material is performed at 30 bar (3000 kPa) and at an initial temperature of 30 ° C, with a heating rate of 3 ° C / min, and increasing. catalyst concentration from 1 to 7%, the GPM / GPS ratio (cis / trans isomers) is reduced from 0.96 to 0.78.

The ratio of cis / trans isomers is reduced from 0.83 to 0.68 while increasing the catalyst concentration from 1 to 7% while working at 130 bar (13000 kPa) with a 50% dry material. isomaltulose at an initial temperature of 30 ° C and a heating rate of 3 ° C / min.

An additional reduction in the cis / trans ratio of isomers is observed between 0.8 to 0.63, while increasing the catalyst concentration from 1 to 7%, working at 80 bar (8000 kPa) of hydrogen gas pressure with a 30% isomaltulose dry material at an initial temperature of 30 ° C and a heating rate of 3 ° C / min.

In another specific embodiment, hydrogenation of a 30% isomaltulose dry material is performed at 30 bar (3000 kPa) at an initial temperature of 20 ° C, in the presence of a 4% catalyst concentration and varying at heating rate from one experiment to another from 0.5 to 4.6 ° C / min, the ratio of cis / trans isomers is increased from 0.61 to 0.74. A ratio as low as 0.57 can be obtained while bringing the heating rate to 0.5 ° C / min at 130 bar (13000 kPa) hydrogen gas pressure. When working with a 50% and 80 bar (8000 kPa) dry isomaltulose material, increasing the heating rate from one experiment to another from 0.5 to 4.3 ° C / min results in an increased ratio. between cis / trans isomers from 0.61 to 0.70.

In another embodiment, hydrogenation of 30% isomaltulose dry material is performed at 80 bar (8000 kPa) with a heating rate of 0.5 ° C / min and increasing the initial temperature from one experiment to another from 20 ° C to 80 ° C. , this increases the ratio of cis / trans isomers from 0.59 to 1.2.

Similar to the described hydrogenation of isomaltulose, the relationships between the epimers obtained from hydrogenation reactions departing from other mono- and oligosaccharides can also be controlled by choosing a specific catalyst concentration by choosing a specific initial temperature and / or by choosing a specific heating rate. In addition, mixtures composed of considerable amounts of more than one ketosis, such as isomaltulose and trehalulose solutions, may be hydrogenated and the stereoisomer ratio obtained may be controlled in accordance with the present invention as illustrated in the examples section.

Another embodiment of the present invention is hydrogenation of fructose solutions. For example, hydrogenation of 30% fructose dry material is performed at 30 bar (3000 kPa) and at an initial temperature of 30 ° C, with a heating rate of 3 ° C / min and increasing the concentration of From 1 to 7% catalyst, the ratio of mannitol / sorbitol (cis / trans isomers) is reduced from 0.89 to 0.71.

In a further specific embodiment, hydrogenation of 30% fructose dry material is performed at 30 bar (3000 kPa) at an initial temperature of 20 ° C, in the presence of a 4% catalyst concentration and varying the rate. heating from one experiment to another from 0.5 to 4.3 ° C / min, the ratios of cis / trans isomers is increased from 0.61 to 0.80.

Similarly, the mannitol / sorbitol ratio obtained can also be controlled by choosing a specific initial temperature and / or by choosing a specific reaction rate of the reaction.

In general, the process according to the invention will be carried out in the liquid phase. In many cases, it may be appropriate to conduct hydrogenation in the presence of a solvent. Basically, all common solvents can be used as long as they do not degrade during hydrogenation reactions. Examples of normal solvents include water, dioxane, tetrahydrofuran, DMSO, methanol, ethanol, n-propane 1, isopropanol, n-butanol, cyclohexanol, ethylene glycol, 1,4-butanediol, 1,6-hexanediol, ethylene glycol dimethyl ether, and mixtures thereof, and the like. In the context of the present invention, however, it is preferable to use water or water-containing reaction mixtures.

After hydrogenation, polyol solutions are usually gutted from the catalyst. In a batch process this can be done primarily by catalyst sedimentation. Thereafter, the remaining catalyst is removed from the supernatant by means of filtration, centrifugation or magnetic separation as completely as possible. Of course, the first sedimentation step does not apply when stuffed bed catalysts are used. In a second step, dissolved components, such as salts, organic acids, proteins, etc., are removed by ion exchange processes. To this end, the solution is treated with weak and / or strong acidity cation exchange resins and with low and / or strong alkalinity anion exchange resins. In addition, undesirable contaminants, such as color, smell and / or taste components, may additionally be removed by adsorption onto active carbon, polishing resins, polymers, etc. Finally, the desired dry material content is adjusted by solvent vaporization.

Sugar alcohols produced in the process according to the invention typically are crystallized, solidified or liquid syrups (concentrated liquid syrups containing 50% or more dry substance). These solidified, crystallized or liquid syrup products or immediate process reaction products can be used in the production of various products. Accordingly, these product mixtures may advantageously be used for coating products in the sweetener or pharmaceutical industry. In addition, candies, especially hard candies, may be prepared from the liquid or viscous product in the process according to the present invention, which is baked at a temperature between 145 ° C and 170 ° C (optionally in the presence of a low vacuum). followed by conventional formatting of the final candy (finally having a water content of less than 4 wt%, preferably less than 2 wt%, based on the weight of the candy).

Other objects and features of the present invention will become apparent from the following detailed description. All% values in the following are given in% by weight unless otherwise indicated.

Examples and detailed description of preferred embodiments Examples 1-3

The following embodiments of the present invention relate to a process for preparing a mixture of 6-OaD-glucopyranosyl-D-sorbitol stereoisomeric sugar alcohols (1,6-GPS) and 1-OaD-glucopyranosyl-D-mannitol (1,1-GPM) by hydrogenation of isomaltulose using a Raney nickel catalyst, where the 1.5-GPS / 1,1-GPM ratio can be adjusted by adjusting the catalyst concentration.

The isomaltulose was hydrogenated in a pressurizable hydrogenation reactor with an internal volume of 1,000 ml (without internal fittings) equipped with an inductively operated mixer, further containing a shaft with a gas stirrer, a sampling valve with a sintered metal frit for sampling. reaction solution and a PT 100 temperature sensor. Mixing was performed at 1220 rpm. The isomaltulose reagent used had the composition shown in table 1

Table 1

Ingredient Content as a dry material Isomaltulose 98.9% Dextrose <0.1% Fructose <0.1% Isomaltose <0.1% Trealulose 0.4% Other 0.5%

The composition of this raw material was analyzed by ion chromatography and HPLC. The amounts of isomaltulose, dextrose, fructose, isomaltose and trehalulose (and, if present, sucrose) were determined on a CarboPac PAl column (Dionex GmbH, Idstein, Germany); The amount of "others", which is mainly oligosaccharides, was determined in a classic Ca2 + cation exchanger, such as an Aminex HPX 87 C ((Bio-Rad Laboratories, Munich, Germany).

The composition of the hydrogenation product samples

obtained were determined on a classic Ca2 + cation exchanger such as Aminex HPX 87 C (Bio-Rad Laboratories, Munich, Germany) except for isomaltulose, which was quantified on a Carbopac PAl column (Dionex GmbH, Idstein, Germany) , if the amount of isomaltose was below 2 wt% on dry basis. Sucrose was determined by enzymatic testing (Art. No. 10 716 260 035, R-Biopharm, Darmstadt, Germany). Example 1

Hydrogenation of isomaltose solution, 50% dry material, 30 bar (3000 kPa).

816 g of aqueous isomaltose solution (50% dry material) was introduced into the autoclave reactor. At a temperature of 30 ° C, the solution was supplemented with 4.1 g, 16.3 g and 28.6 g of nickel catalyst (Degussa, BK 111 W), respectively, corresponding to 1%, 4% and 7% of nickel. catalyst, respectively, based on the dry sugar content of the isomaltose solution. The reactor was closed and inertized three times with nitrogen. Nitrogen was replaced by hydrogen three times and thereafter the hydrogen pressure was adjusted to 30 bar (3000 kPa). The rotation speed was increased to 1220 rpm and the isomaltose solution was heated from 30 ° C to 130 ° C with a heating rate of 3 ° C / min. The hydrogen consumed was automatically replenished so that the 30 bar (3000 kPa) pressure was maintained throughout the course of the hydrogenation reaction. Samples were obtained when the temperature of 130 ° C was reached, having the compositions shown in table 2. Table 2

Catalyst concentration 1 4 7 [% dry sugar] Heating rate [° C / min] 3 3 3 GPS * [% dry sugar] 48.3 53.9 55.5 1.1-GPM [% sugar dry] 46.5 45.1 43.6 Sorbitol [% dry sugar] 0.1 0.1 0.1 Mannitol \% dry sugar] 0.1 0.1 0.1 Isomaltulose [% dry sugar] 3.5 <0.05 <0.05 Other [% dry sugar] 1.5 0.9 0.8 GPM / GPS Ratio 0.963 0.837 0.786 GPS *: GPS consists mainly of 1.6-GPS and small amounts of 1,1 -GPS, the latter being formed from trehalulose. 1,1-GPS and 1,6-GPS are eluted simultaneously in the HPLC method used.

It is evident from Table 2 that the GPM / GPS ratio is dependent on the catalyst concentration at the constant heating rate. The ratio of cis / trans isomers (GPM / GPS) is reduced with increased catalyst concentration.

The reaction containing 1% catalyst was continued for an additional 1h at 130 ° C to demonstrate that the reaction can be completed, and the remaining isomaltose content can be reduced below 0.05% without significantly altering the obtained GPM / GPS ratio.

Example 2

Hydrogenation of isomaltose solution, 50% dry material, 130 bar (13000 kPa)

816 g of isomaltose solution (50% dry material) was introduced into the autoclave reactor. At a temperature of 30 ° C solution 15 was supplemented with 4.1 g, 16.3 g and 28.6 g of nickel catalyst (Degussa, BK 111 W), respectively, corresponding to 1%, 4% and 7% of catalyst, respectively, based on the dry sugar content of the isomaltulose solution. The reactor was closed and inertized three times with nitrogen. Nitrogen was replaced with nitrogen three times and thereafter the hydrogen pressure 20 was set to 130 bar (13000 kPa). The rotation speed was increased to 1220 rpm and the isomaltose solution was heated from 30 ° C to 130 ° C with a heating rate of 3 ° C / min. The hydrogen consumed was automatically replenished so that the pressure of 130 bar (13000 kPa) was maintained throughout the course of the hydrogenation reactions. Samples were obtained when the temperature of 130 ° C was reached, having the compositions shown in table 3.

Table 3

Catalyst concentration 1 4 7 [% dry sugar] Heating rate [° C / min] 3 3 3 GPS * [% dry sugar] 53.8 57.6 58.9 1.1-GPM [% sugar dry 45.0 41.6 40.3 Sorbitol [% dry sugar] 0.1 0.1 0.1 Mannitol [% dry sugar] 0.1 0.1 0.1 Isomaltulose [% dry sugar] <0.05 <0.05 <0.05 Other [% of dry sugar] 1.0 0.7 0.6 GPM / GPS ratio 0.836 0.722 0.684 It is evident from Table 3 that the GPM / GPS ratio is

dependent on catalyst concentration at constant heating rate. The cis / trans ratio of isomers (GPM / GPS) decreases with increasing catalyst concentration.

Example 3

Isomaltose solution hydrogenation, 30% dry material, 80 bar (8000 kPa)

746 g of aqueous isomaltose solution (30% dry material) was introduced into the autoclave reactor. At a temperature of 30 ° C the solution was supplemented with 2.2 g, 9.0 g and 15.7 g of nickel catalyst (Degussa, BK 111 W), respectively, corresponding to 1%, 4% and 7% of catalyst, respectively, based on the dry sugar content of the isomaltose solution. The reactor was closed and inertized three times with nitrogen. Nitrogen was replaced with hydrogen three times and thereafter the hydrogen pressure 20 was set to 80 bar (8000 kPa). The rotation speed was increased to 1220 rpm and the isomaltulose solution was heated from 30 ° C to 130 ° C with a heating rate of 3 ° C / min. The hydrogen consumed was automatically replenished so that the 80 bar (8000 kPa) pressure was maintained throughout the course of the hydrogenation reaction. Samples were obtained when the temperature of 130 ° C was reached, having the compositions shown in table 4.

Table 4

Catalyst concentration 1 4 7 [% dry sugar] Heating rate l ° C / min] 3 3 3 GPS * [% dry sugar] 54.6 58.7 60.7 1.1-GPM [% sugar 44.1 40.5 38.6 Sorbitol [% dry sugar] 0.1 0.1 0.1 Mannitol [% dry sugar] 0.1 <0.05 0.1 Isomaltulose [% dry sugar] ] 0.1 <0.05 <0.05 Other [% dry sugar] 1.1 0.6 0.5 GPM / GPS ratio 0.808 0.690 0.636 It is evident from Table 4 that the GPM / GPS ratio is

dependent on catalyst concentration at constant heating rate. The cis / trans ratio of isomers (GPM / GPS) is reduced with increasing catalyst concentration.

Example 4

Hydrogenation of isomaltulose / trehalulose solution, 30% dry material, 30 bar (3000 kPa)

Table 5

Ingredient Content as a dry material Isomaltulose 85.8% Dextrose 1.5% Fructose 2.6% Isomaltose 0.5% Trealulose 8.0% Sucrose 0.1% Other 1.5% 746 g of aqueous isomaltulose / trehalulose solution (30% dry material) of the composition shown in table 5 (quantification according to the method explained for examples 1-4) were introduced into the autoclave reactor. At a temperature of 30 ° C, the solution was supplemented with 2.2 g, 9.0 g and 15.7 g of nickel catalyst (Degussa, BK 111 W), respectively, corresponding to 1%, 4% and 7%. respectively based on the dry sugar content of the isomaltulose / trehalulose solution. The reactor was closed and inertized three times with nitrogen. Nitrogen was replaced by hydrogen three times and thereafter the hydrogen pressure was adjusted to 30 bar (3000 kPa). The rotation speed was increased to 1220 rpm and the 5 isomaltulose / trehalulose mixture was heated from 30 ° C to 130 ° C with a heating rate of 3 ° C / min. The hydrogen consumed was automatically replenished so that the 30 bar (3000 kPa) pressure was maintained throughout the course of the hydrogenation reaction. Samples were obtained when the temperature of 130 ° C was reached and the compositions shown in Table 6 (quantification according to the method explained for examples 1-3).

Table 6

Catalyst concentration 1 4 7 [% dry sugar] Heating rate [° C / min] 3 3 3 GPS * [% dry sugar] 44.8 52.4 54.4 1,1-GPM [% sugar 40.5 41.3 39.4 Sorbitol [% dry sugar] 2.1 3.1 3.1 Mannitol \% dry sugar] 1.2 1.2 1.2 Isomaltulose [% dry sugar] 5.5 <0.05 <0.05 Others [% dry sugar] 6.0 1.9 1.9 GPM / GPS ratio 0.904 0.788 0.724 It is evident from Table 6 that the GPM / GPS ratio is dependent on the concentration of catalyst at constant heating speed. The ratio of cis / trans isomers (GPM / GPS) is reduced with increasing catalyst concentration.

The reaction containing 1% catalyst was continued for a further 1h at 130 ° C to demonstrate that the reaction can be completed and the remaining isomaltulose content can be reduced below 0.05% without significantly altering the obtained GPM / GPS ratio.

Example 5

Hydrogenation of fructose solution, 30% dry material, 30 bar (3000 kPa) 751 g aqueous fructose solution (30% dry material, composition: 99.7% fructose; 0.2% dextrose; 1% others, the composition was analyzed by HPLC using a classic Ca2 + form cation exchanger such as Aminex HPX 87 C (Bio-Rad Laboratories, Munich, Germany)) were introduced into the autoclave reactor. At a temperature of 30 ° C the solution was supplemented with 2.3 g, 9.0 g and 15.8 g of nickel catalyst (Degussa, BK 111 W), respectively, corresponding to 1%, 4% and 7% of catalyst, respectively, based on the dry sugar content of the fructose solution. The reactor was closed and inertized three times with nitrogen. Nitrogen was replaced with hydrogen three times and 10 thereafter the hydrogen pressure was adjusted to 30 bar (3000 kPa). The speed of rotation was increased to 1220 rpm and the fructose mixture was heated from 30 ° C to 130 ° C with a heating rate of 3 ° C / min. The hydrogen consumed was automatically replenished so that the 30 bar (3000 kPa) pressure was maintained throughout the course of the hydrogenation reaction. Samples were obtained when the temperature of 130 ° C was reached, having the compositions shown in table 7.

The composition of the hydrogenation product compositions

• · · 2+

was determined on a classic Ca-shape cation exchanger such as the

Aminex HPX 87 C (Bio-Rad Laboratories, Munich, Germany), except for fructose, which was determined by an enzymatic test (Art. No. 10 716 260 035, R-Biopharm, Darmatadt, Germany), if the amount of Fructose was below 1 wt% on dry basis.

Table 7

Catalyst concentration 1 4 7 [% dry sugar] Heating rate [° C / minl 3 3 3 D-Sorbitol [% dry sugar] 47.1 56.5 58.2 D-Mannitol [% dry sugar] 42.3 43.1 41.5 L-Iditol [% dry sugar] <0.05 0.1 0.1 D-Fructose [% dry sugar] 9.8 <0.05 <0.05 Other [ % dry sugar] 0.8 0.3 0.2 Mannitol / Sorbitol Ratio 0.898 0.763 0.713 It is evident from Table 7 that the mannitol / sorbitol ratio is also dependent on the catalyst concentration at a constant rate of heating. The cis / trans ratio of isomers (mannitol / sorbitol) is reduced with increasing catalyst concentration.

The reaction containing 1% catalyst was continued for an additional 1h at 130 ° C to demonstrate that the reaction can be completed and the remaining fructose content can be reduced below 0.05% without significantly altering the obtained mannitol / sorbitol ratio.

These data demonstrate that the dependence of the ratio of isomers obtained by hydrogenation on catalyst concentration is a general principle observable with different reagents.

Examples 6-8

The following embodiments of the present invention relate to a process for the preparation of a mixture of 6-OaD-glucopyranosyl-D-sorbitol stereoisomeric sugar alcohols (1,6-GPS) and 1-OaD-glucopyranosyl-D-mannitol (1 (1-GPM) by hydrogenation of isomaltulose using a Raney nickel catalyst at an increased hydrogen pressure, where the 1.6-GPS / l, I-GPM ratio can be controlled by changing the heating rate of the mixture. reaction. Isomaltulose reagent is specified in table 1 (above). The isomaltulose was hydrogenated as described for examples 1-3 with different initial temperatures as mentioned in the following examples. For the analysis of the samples obtained from hydrogenation product, the same procedures mentioned above were used.

Example 6

Hydrogenation of isomaltulose solution, 30% dry material, 30 bar (3000 kPa)

746 g of aqueous isomaltulose solution (30% dry material) introduced into the autoclave reactor was supplemented with 9.0 g of nickel catalyst (Degussa, BK 111 W), corresponding to 4% catalyst based on the content. of dry material from the isomaltulose solution. The reactor was closed and inertized twice with nitrogen. Nitrogen was replaced with hydrogen twice and thereafter the hydrogen pressure was adjusted to 30 bar while mixing at 333 rpm. The rotation speed was increased to 1220 rpm and the isomaltulose solution was heated from about 20 ° C to 130 ° C in different experiments with a heating rate of 0.5 ° C / min, 1.0 ° C / min, 2.7 ° C / min or 4.6 ° C / min, respectively. The hydrogen consumed was automatically replenished so that the 30 bar (3000 kPa) pressure was maintained throughout the course of the hydrogenation reaction. In each experiment, a sample was obtained when the temperature reached 130 ° C, having the composition shown in table 8.

Table 8

Starting temperature [0C] 20 20 20 20 Ending temperature [° C] 130 130 130 130 Heating rate [° C / min] 0.5 1.0 2.7 4.6 GPS * [% dry sugar] 61, 4 60.4 58.2 56.9 1.1-GPM [% dry sugar] 37.8 ^ 38.9 41.0 42.2 Sorbitol [% dry sugar] 0.1 0.1 0.1 0.1 Mannitol [% dry sugar] <0.05 <0.05 <0.05 <0.05 Isomaltulose [% dry sugar] <0.05 <0.05 <0.05 <0.05 Other [% bez. TS] 0.6 0.6 0.7 0.8 GPM / GPS Ratio 0.616 0.644 0.704 0.742 It is evident from Table 8 that the GPM / GPS ratio is dependent

heating rate of the reaction mixture. The ratio of cis / trans isomers (GPM / GPS) increases with increasing heating rate.

Example 7

Hydrogenation of isomaltulose solution, 30% dry material, 80 and 130 bar (8000 and 13000 kPa)

Similar reactions to example 6 were performed at various heating speeds under different hydrogen pressures (see table 9). In addition to adjusting the hydrogen pressure to 80 bar and 130 bar (80 00 and 13000 kPa), respectively, and maintaining these pressures throughout the reaction, the conditions described above remained unchanged.

The obtained GPM / GPS ratios are summarized in table 9.

Table 9

Heating Rate Isomaltulose (80 bar) Isomaltulose (130 bar) [° C / min] (8000 kPa) (13000 kPa) 0.5 0.587 0.576 1.0 0.609 0.590 Example 8

Hydrogenation of isomaltulose solution, 50% dry material, various pressures

816 g of aqueous isomaltulose solution (50% dry material), introduced into the autoclave reactor, was supplemented with 16.3 g of nickel catalyst (Degussa, BK 111 W), corresponding to 4% of 10 catalyst based in the dry material content of the isomaltulose solution. The reactor was closed and inertized twice with nitrogen. Nitrogen was replaced with hydrogen twice and thereafter the hydrogen pressure was adjusted to 80 bar (8000 kPa) while mixing at 333 rpm. The rotation speed was increased to 1220 rpm and the isomaltulose solution 15 was heated from about 20 ° C to 130 ° C at various heating speeds, respectively. The hydrogen consumed was automatically replenished so that the 80 bar (8000 kPa) pressure was maintained throughout the course of the hydrogenation reaction. Samples were obtained when the temperature of 130 ° C was reached, having the compositions shown in table 10.

Table 10

Hydrogen pressure [bar] 80 80 80 80 Starting temperature [° C] 20 20 20 20 Ending temperature [0C] 130 130 130 130 Heating rate [° C / min] 0.5 1.0 2.9 4.3 GPS * [% of dry material] 61.5 60.8 59.2 58.1 1.1-GPM [% of dry material] 37.8 38.5 40.0 41.0 Sorbitol [% of dry material] 0.1 0.1 0.1 0.1 Mannitol [% dry matter] <0.05 <0.05 0.1 0.1 Isomaltulose [% dry material] <0.05 <0.05 <0 .05 <0.05 Others [% dry matter] 0.6 0.6 0.7 0.8 GPM / GPS ratio 0.615 0.633 0.676 0.706 It is evident from Table 10 that the GPM / GPS ratio is dependent on the heating rate. of the reaction mixture.

Similar experiments were performed at 30 bar and 130 bar (3000 and 13000 kPa) hydrogen pressures, respectively. These results (GPM / GPS ratio) are summarized in table 11.

Table 11

Isomaltulose Rate (30 bar) Isomaltulose (80 bar) Isomaltulose (130 bar) heating (3000 kPa) (8000 kPa) (13000 kPa) [° C / minl 0.5 0.650 0.615 0.602 1.0 0.673 0.633 0.620 2.9 0.754 0.676 0.650 4.3 0.706 4.4 0.672 4.6 0.810 These results demonstrate that the dependence on the

heating is maintained over a wide range of applied pressures of H2.

Example 9

Hydrogenation of isomaltulose solution, 30% dry material, 80 bar (8000 kPa) with an initial temperature of 80 ° C

746 g of aqueous isomaltulose solution (30% dry material) was introduced into the autoclave reactor and heated to 80 ° C while stirring. 9.0 g of nickel catalyst (Degussa, BK 111 W) corresponding to 4% catalyst was added based on the dry material content of the isomaltulose solution. The reactor was closed and inertized twice with nitrogen. Nitrogen was replaced by hydrogen twice and thereafter the hydrogen pressure was adjusted to 80 bar (8000 kPa). During the reaction, the solution was stirred at 1220 rpm and the temperature was raised to 130 ° C at various heating speeds, respectively. The hydrogen consumed was automatically replenished so that the 80 bar (8000 kPa) pressure was maintained throughout the course of the hydrogenation reaction. Samples were obtained when the temperature of 130 ° C was reached, having the compositions shown in table 12.

Table 12

Starting Temperature [0C] 80 80 Final Temperature [° C] 130 130 Heating Rate [° C / min] 0.5 1.0 GPS [% Dry Material] 45.7 45.1 1.1-GPM [% of Dry Material] 52.9 53.3 Sorbitol [% Dry Material] 0.1 0.1 Mannitol [% Dry Material] 0.1 0.1 Isomaltulose [% Dry Material] <0.05 <0.05 Other [% dry matter] 1.2 1.4 GPM / GPS Ratio 1.158 1.82 Example 10

Hydrogenation of fructose solution, 30% dry material, 30 bar (3000 kPa) 751 g aqueous fructose solution (30% dry material,

composition: 99.7% fructose; 0.2% dextrose; 0.1% others; The composition was analyzed by HPLC using a classic Ca2 + form cation exchanger such as Aminex HPX 87 C (Bio-Rad Laboratories, Munich, Germany)) and introduced into the autoclave reactor 10 described above, supplemented with 9.0 g of nickel catalyst (Degussa, BK 111 W), corresponding to 4% catalyst based on the dry material content of the fructose solution. The reactor was closed and inertized twice with nitrogen. Nitrogen was replaced by hydrogen twice and thereafter the hydrogen pressure was adjusted to 30 bar (3000 kPa) 15 while mixing at 333 rpm. The rotation speed was increased to 1220 rpm and the fructose solution was heated from about 20 ° C to 130 ° C with various heating speeds, respectively. The hydrogen consumed was automatically replenished so that the 30 bar (3000 kPa) pressure was maintained throughout the course of the hydrogenation reaction. Twenty samples were obtained when the temperature of 130 ° C was reached, having the compositions presented in table 13.

The composition of the hydrogenation product compositions

2+

was determined on a classical Ca-form cation exchanger such as Aminex HPX 87 C (Bio-Rad Laboratories, Munich, Germany) except for fructose, which was determined by an enzymatic test (Art. No. 10 716 260 035, R-Biopharm, Darmstadt, Germany), if the amount of fructose was below 1 wt% on dry basis.

Table 13

Starting Temperature [0C] 20 20 20 20 Ending Temperature [0C] 130 130 130 130 Heating Rate [° C / min] 0.5 1.0 2.9 4.3 D-Sorbitol [% Dry Material] 61, 7 60.2 57.0 55.1 D-Mannitol [% dry material] 37.9 39.4 42.5 44.0 L-Iditol [% dry material] 0.2 0.2 0.1 0 D-Fructose [% dry matter] <0.05 <0.05 <0.05 0.2 Other [% dry matter] 0.2 0.3 0.4 0.5 Mannitol / Sorbitol Ratio 0.614 0.654 0.746 0.799 It is apparent from the table of 13 that the mannitol / sorbitol ratio is dependent on the heating rate of the reaction mixture. The ratio of cis / trans (mannitol / sorbitol) isomers increases with increasing heating rate.

Example 11

Hydrogenation of isomaltulose / trehalulose solution, 30% dry material, 30 bar (3000 kPa)

746 g of aqueous isomaltulose / trehalulose solution (30% dry material) of a composition shown in table 6 (see example 5; quantification according to the method explained for examples 1-4) were introduced into the autoclave described above, and were supplemented with 9.0 g of nickel catalyst (Degussa, BK 111 W), corresponding to 4% catalyst based on the dry material content of the isomaltulose / trehalulose solution. The reactor was closed and inertized twice with nitrogen. Nitrogen was replaced with hydrogen twice and thereafter the hydrogen pressure was adjusted to 30 bar (3000 kPa) while mixing at 333 rpm. The rotation speed was increased to 1220 rpm and the isomaltulose / trehalulose solution was heated from about 20 ° C to 130 ° C with various heating speeds, respectively. Hydrogen consumption was automatically reset so that the 30 bar pressure was maintained during the course of the hydrogenation reaction. Samples were obtained when the temperature of 130 ° C was reached, having the compositions shown in table 14 (quantification according to the method explained for examples 1-3).

Table 14

Starting Temperature [0C] 20 20 20 20 Ending Temperature [0C] 130 130 130 130 Warming Rate [° C / min] 0.5 1.0 3.0 4.7 GPS * [% Dry Material] 56.7 55.7 53.7 52.5 1.1-GPM [% dry material] 37.1 38.2 40.1 41.1 Sorbitol [% dry material] 3.2 3.1 3.1 3, 0 Mannitol [% dry material] 1.1 1.2 1.2 1.2 Isomaltulose [% dry material] <0.05 <0.05 <0.05 <0.05 Sucrose [% dry material] 0.1 0.1 0.1 0.1 Other [% of dry material] 1.8 1.7 1.8 2.1 GPM / GPS ratio 0.654 0.686 0.747 0.783 It is evident from Table 14 that the GPM / GPS ratio It's

dependent on the heating rate of the reaction mixture.

The data from the last two examples further demonstrate that the dependence of the isomer ratio obtained by hydrogenation on the heating rate is a general principle observable with different reagents and different mixtures.

Claims (12)

1. A process for the controlled hydrogenation of a ketosis or a ketosis-containing sugar mixture to produce a product mixture composed of at least two stereoisomeric sugar alcohols in a predefined relationship between the cis isomer and the trans isomer. ) producing a reaction mixture composed of said ketosis or the ketosis-containing sugar mixture, (b) adding to said reaction mixture a concentration of nickel-based solid catalyst based on the dry sugar content of the ketosis or sugar mixture containing ketosis, preferably a Raney nickel concentration, and c) carrying out in said mixture a reaction of a hydrogenation reaction in the presence of hydrogen gas, characterized in that the process is composed of a heating step, and where the ratio between cis isomer and trans isomer is reduced iv) increasing the concentration of the nickel-based solid catalyst, preferably Raney nickel, v) reducing the initial temperature of the heating step, and / or vi) reducing the heating rate of the nickel-based step. heating. Process according to Claim 1, characterized in that the ketosis or the ketosis-containing sugar mixture is chosen from the group consisting of fructose, sorbose, erythrulose, lactulose, trehalulose, maltulose, isomaltulose, leucrose, fructooligosaccharides, and a mixture thereof. preferably isomaltulose, trehalulose, fructose, and mixtures thereof. Process according to Claim 1 or 2, characterized in that the reaction mixture is an aqueous solution composed of ketosis or a ketosis-containing sugar mixture, in a concentration of 10% to 70% by weight. Process according to any one of the preceding claims, characterized in that the hydrogenation is carried out at a hydrogen pressure between about 10 and 450 bar (1000 and 45000 kPa). Process according to any one of the preceding claims, characterized in that the concentration of nickel-based solid catalyst is between 0.5% and 10% by weight, preferably between 2% and 7% by weight. the dry sugar content of the ketosis or a sugar mixture containing ketosis. Process according to any one of the preceding claims, characterized in that the heating rate is less than 6 ° C / min. Process according to any one of claims 1-5, characterized in that the heating rate is in the range 0.5 to 5.0 ° C / min. Process according to any one of the preceding claims, characterized in that the heating step is implemented by a heating rate from the initial temperature (Tj) to an end temperature (T2) with a temperature difference of at least T2-Ti. 20 ° C, preferably at least 30 ° C. Process according to any one of the preceding claims, characterized in that the hydrogenation reaction is carried out at a temperature between 20 ° C and 150 ° C. Process according to any one of claims 1-8, characterized in that the hydrogenation reaction is carried out at a temperature between 30 ° C and 130 ° C, preferably 90 ° C. Process according to any one of the preceding claims, characterized in that the reaction mixture is composed of isomaltulose such that said at least two stereoisomeric sugar alcohols are 1-OaD-glucopyranosyl-D-mannitol ( 1,1-GPM) and 6-OaD-glucopyranosyl-D-sorbitol (1,6-GPS). Process according to any one of claims 1-10, characterized in that the reaction mixture is composed of fructose, such that said at least two stereoisomeric sugar alcohols are composed of mannitol and sorbitol.